Ops! Sorry, my bad! I am getting confused already!
Well, in that case, I can confirm that it worked. I created both new page and new custom post type article, and they came with 404 marked as default after the coding! Great job!
Good news – I repeated a described issue. Trying to open prohibited by URE (action HTTP 404) page with active wOffice 2.4 does not show theme’s 404 page. Trying to open really unexisted page shows theme’s 404 as expected.
So I will investigate a reason of this conflict and contact your then, may be tomorrow.
A quick fix for the empty 404 page problem is to add lower priority to the URE Pro’s post filter. You can open user-role-editor-pro/pro/includes/classes/content-view-restrictions-posts-list.php and replace line #17
A reason of this conflict the woffice theme applies its posts restrictions filter even if restricted posts list is empty. Applying this filter theme overwrites the same filter set by URE Pro little earlier. So a restricted page exists for WordPress and WP tries to show it, but with empty content as URE does not allow to view content of restricted post here too.